System of control



H. H. JOHNSTON.

SYSTEM OF CONTROL. APPLICATION FILED JAN. 14, 1921.

1,435,241 Patented Nov. 14, 1922.

WITNESSES! INVENTOR zeiii 4/27: i022. fly BY F I Patented Nov. 14, 1922.

UNITED STATES 1,435,241 PATENT OFFICE.

HOWARD H. JOHNSTON, OF EDGEWOOD PARK, PENNSYLVANIA, ASSIGNOR T0 WEST- INGHOUSE ELECTRIC & MANUFACTURING COMPANY, A CORPORATION OF PENN- SYLVANIA.

SYSTEM OF CONTROL.

Application filed January 14, 1921; Serial No. 437,156.

To all whom it may concern:

Be it known that I, HOWARD H. JOHNSTON, a citizen of the United States, and a resident of Edgewood Park, in the county of Allegheny and State of Pennsylvania, have iii-- 1 vented a new and useful Improvement in Systems of Control, of which the following is a specification. I

My invention relates to motor-control systems and it has particular relation to such systems .as are employed in connection with so-called safety cars of electric railways.

The object of my invention is to provide means operable, in case of emergency, to interrupt the operating circuit andto actuate the air brakes.

Another object of my invention is to eliminate circuit breakers from the car platform and to simplify the usual means for controlling the main circuit.

In the present system, it is proposed to rovide a small fluid-pressure-operated reay, in a convenient location, which receives pressure upon the release of the operators controller handle. This relay controls a circuit for the actuating coil of a line wntactor. For convenience, a foot valve is connected in the emergency pipe line for preventing the interruption, of the main-line circuit in cases where it is necessary for the operator to remove his hand from the controller. In case the operator leaves his position, the controller and the car become inoperative.

My invention will be described in connec tion with the accompanying drawing, in which a single figure represents, diagram matically, apparatus and circuits embodying my invention.

A controller 1 controls an electrical circuit comprising a line contactor 2, an overload relay 3 and a line conductor 4. A fluid-pressure-operated relay 5 is connected, by a control switch 6, to the operating circuit of the line contactor 2. The relay 5 is operatively connected to the controller 1 through a pipe 7, and the emergency valve 8, which is connected to any well-known system for supplying fluid pressure, such as is in common use in railway systems, for operating the brakes.

In the first operative position of the coir troller, a circuit is established for the operating coil of the line contactor 2, extending from the positive line conductor 4, through conductor 9, contact members 11 and 12, conductor 13, relay 5, conductor 14, contact members 15, 16 and 17, conductor 18, relay 3, coil 19, conductor 21 and contact members 22 and 23, to ground. The contactor 2 closes and a circuit is established from positive line conductor 4, through the line contactor 2, overload-relay coil 24, contact members 25, 26 and 27 and motor 28 to ground. The controller 1 may now be actuated to its second operative position, maintaining circuits which have previously been traced, excepting the circuit comprising contact members 22 and 23. These members engage only in the first operative position of the controller. A holding circuit, however, is established for coil 19 extending from the positive line eontactor 4, through conductor 9, contact members 11 and 12, conductor 13, relay 5, conductor 14, contact members 15, 16 and 17, conductor 18, relay 3, coil 19, interlock 29 and conductor 31, to ground. The operating circuit is now complete.

The controller handle 32 is depressed in its normal operation and the relay 5 establishes the engagement of its contact members 33, 34 and Upon release of the handle 32, fluid pressure is admitted, through the pipe 7 and the emergency valve 8, to an air cylinder 36, and to the air-brake system which is not a part of this invention. A plunger 37, carrying contact member 34, is operated by fluid pressure in the cylinder 36 so that contact member 34 is actuated vertically out of engagement with contact members 33 and 35 upon admission of pressure to the cylinder 36. The interruption of the control circuit established by the relay 5 interrupts a circuit for the coil 19, previously traced, and which can be re-established only by returning the controller to the first operative position. The car, therefore, immediately becomes inoperative.

In case the operator finds it necessary to release the lever 32, but desires to maintain the operating circuit uninterrupted, he will actuate a foot valve 38, preventing admission of air to the cylinder 36. The operator is, therefore, free for the manipulation of other apparatus requiring attention. It is impos sible, however, for the operator to move any considerable distance from the controller without removing his foot from the foot valve. This afiords means for protection which is at once obvious.

In case of overload, the customary protection is provided by means of overload relay 3, the function of which is sufiiciently Well known to require no description. Also, an air-brake system is provided comprising the standard equipment from Which we ob tain fluid pressure for emergency operation, as has been described.

I have described a system which is applicable to any suitable railway equipment but is particularly adapted to one-man or safety-car control equipment. Circuit breakers have been eliminated from the car platforms, 'WQll as circuit-breaker air cylinders and the piping usually necessary tor their operation. Fire hazard and danger or discomfort to operators or passengers are minimized by the elimination of the circuit breakers. The system may be used in conjunction with controllers of standard manufacture.

Fluid pressure need not be applied continuously to the relay cylinder, since the momentary interruption the electric-control. circuit results in the interruption of the main circuit, which circuit is only reestabl shed upon the return of the controller to a predetermined position.

I claim as my invention z 1. The combination With an electrical circuit and a manually operated controlling device having a plurality of operative p0sitions, oi? a line contactor, a relay for controlling the contactor and means comprising said controlling device for actuating the relay, in any of said operative positions.

2. The combination With an electrical circuit and a circuit-controlling device therefor, of a fluid-pressure responsive relay for controlling said device, and means for applying fluid-pressure to the relay for actuating said controlling device, to interrupt the electrical circuit.

d. The combination with an electrical circuit andcontrolling means therefor comprising a line contactor, of means for connecting the operating coil or the line contactor in circuit, a fluid-operated relay for controlling said operating coil, and means operable With the connecting means for controlling the fluid pressure.

t. The combination with electrical cir cuit and a controlling device therefor comprising a line contactor, of a manually operated controller, and a relay, actuated, when the controller handle is released, for interruptinga circuit for controlling the line contactor. r

5. The combination with an electrical circuit and a controlling device therefor comprising a line contactor, of a manually operated controller having a plurality of operative positions, one of which controls a circuit for the coil of the line contactor, and a relay, actuated, when the controller handle is released, for interrupting a circuit for controlling a line contactor.

6. The combination with an electrical circuit and a line contactor, oi a manually operated controller having a plurality of operative positions, one or which positions is for controlling the contactor, int rloeking means for maintaining said contactor in its closed position in other operative positions of said controller, a fluid-pressure-responsive relay for controlling said contactor inde peudently of said maintaining means, means comprising said controller handle for controlling the fluid pressure, and means comprising a foot valve for independently controlling said pressure.

In testimony whereof, I have hereunto subscribed my "name this 5th day of January, 1921.

HOWARD n. JOHi error. 

